The present invention relates to wireless local area network association device and process and to corresponding products.
For associating a new product in a wireless local area network, henceforth referred to as WLAN, it is generally necessary to have an access point node in the network, which is provided by one of the apparatus of the network. Notably, this apparatus may be a modem, such as for example a DSL modem (for “Digital Subscriber Line”). The product to be connected to form a new node may be for example a wireless set-top-box, video streamer or Internet audio device, VoIP (for “Voice over Internet Protocol”).
Two different criteria have been deemed important for wireless associations. First, it is recommended that the operations to be executed by the user remain friendly, and do not require too many and complicated actions. Secondly, the association is risky, because a non-authorized person could try to remotely connect in order to obtain confidential information from the network. Thus, security constitutes a second important aspect to take care of.
Those two criteria have proved relatively difficult to reconcile, because security mechanisms generally require some specific operations or data input from the user, which can be laborious, or dedicated additional material. On the other hand, increased user-friendliness often tends to go hand-to-hand with a decrease in security level, as compensation for a reduction in the connection steps and necessary data input required.
A current solution thus comprises a step of manual configuration of the device to be connected, herein below called “station”, with an identifier of the network or of a cell covered by one or several access points. That identifier is currently known as an SSID (for “Service Set. IDentifier”). A security key is also configured in the station, that key being compliant with a wireless security standard such as notably WEP (for “Wired Equivalent Privacy”) or WPA (for “Wi-Fi Protected Access”, standard introduced by the Wireless Ethernet Compatibility Alliance—WECA, and being a subset of IEEE 802.11i). Then, the station is able to associate to the correct access point.
That solution requires prior entry of necessary data by the user in the device to be connected, which may be rather tedious for long size data. Furthermore, the station may not provide a full keyboard but only a simple remote control for entering the data. This is usually the case when the station is not a PC (for “Personal Computer”) but for example a wireless multimedia device or telephone. It may thus be necessary for the user to access the relevant characters one after the other, to scroll through a virtual keyboard displayed on a terminal (e.g. television screen), so as to enter the correct SSID and security key. Only then is the device liable to associate.
That process can be rather lengthy and frustrating. Indeed, the security key alone can be up to 26 characters, which are typically displayed as asterisks (for security), so that a mistake is easily done. Also, if association fails, there is no indication of the failure reason.
Document US-2003/031151 concerns a roaming technique in wireless local area networks. A packet gateway node (noted “PGN”) acts as a mobile IP (for “Internet Protocol”) home agent with authentication of a mobile node (noted “MN”) handled by a GPRS/UMTS network (for “General Packet Radio Service” and “Universal Mobile Telecommunication System”), before the packet gateway node ever sees data traffic to establish a mobile IP authentication key. A shared key may be established by an unauthenticated key exchange method such as notably Diffie-Hellman method. Thus, a shared secret key and a security association are set between the MN and the PGN. An authentication value obtained from hashing the key and a security parameters index derived from the security association are then used at the PGN for authenticating the MN. In that way, when the MN sends a mobile IP registration request to the PGN, authentication is performed and the PGN sends back a mobile IP registration reply.
That technique simplifies connection of mobile nodes to WLAN networks for portable cellular phones. However, initial establishment of the key between the MN and the PGN is unauthenticated, and therefore leaves some flaws in the security. Consequently, though quite adapted to the field of portable cellular phones, the system does not appear completely satisfactory in other cases, notably for wireless home networks.
Document U.S. Pat. No. 5,539,824 describes a method for safe key distribution and authentication in a data communication network, notably in a WLAN. Individual remote stations are thus wirelessly connected to an installed base station. For achieving security by reliably authenticating the exchanges of data between communication parties, session keys are established and distributed to the network components. For that, a first installed base station is used to generate a network key and a backbone key, and to subsequently install additional base stations while avoiding communication of the network key through the wireless network—the network key being for example transmitted via wired network circuits.
Though that technique provides a reliable security level, it requires specific operations by the user for safely transferring the network key data from the first installed station to the next ones. Further, it does not solve the problem for the installation of the first base station.
Document US-2003/0169713 concerns a zero-configuration secure mobility networking technique for WLAN, relying on a Web-based authentication. A link-layer authentication process facilitates network-to-user authentication and generation of session-specific encryption keys for air traffic using digital certificates. A Web-based authentication server uses a Web page for initial authentication and a Java applet for consequent authentications. Once a user is authenticated to the WLAN, a mobile host of that user obtains full IP connectivity and receives secure mobility support from the WLAN.
In that technique, security provisions are thus delegated to a central server in the network. This leaves the possibility of some potential piracy intrusion into the server, to obtain relevant authentication data and later gaining unauthorized access to the WLAN.
Document US-2002/0061748A1 describes a technique for securely and easily registering and authenticating a wireless base station and a wireless terminal in a WLAN. The registration is carried out first by the public key cryptosystem of the terminal, and then the authentication is carried out by the secret cryptosystem of the base station.
Though that technique simplifies connection of mobile nodes to WLAN, it offers a limited level of security with the insecure WEP algorithm of 802.11.
Further, Thomson Company has commercialized a DSL modem under the name of “Speed Touch 570”, which provides for secure association mechanism in a WLAN, in a simple way for the user. The modem comprises a special touch to be pressed by a user for opening a time window, during which a station may be associated with the network. Prior to pressing the touch, the user must have first registered the relevant parameters in that station (the SSID, which is here implemented as a key). Therefore, when association is required, the user has just to push one button and all further steps are done automatically.
Though the association is user-friendly, it requires preliminary recording of relevant parameters in the station. Also, security could be improved, since only the SSID is recorded in the station as a key and only the MAC address (for “Medium Access Control” of IEEE 802.11 standard) of the client is registered in the modem. However, entering also a special security key would involve additional prior operations by the user.